The present invention relates to digital video teleconferencing. In particular, it relates to sending data of images of different resolution and different coverage to enable a remote viewer of an event to have a richer and more detailed viewing experience.
Video teleconferencing for business and pleasure purposes is becoming increasingly important and more convenient. For example, it is becoming common to present lectures at remote classrooms and to provide business presentations to multiple sites, and it is possible for a user to receive video conferencing feeds on a home computer.
With the increasing popularity of digital video teleconferencing, it is desirable to economically achieve a greater versatility and wider range of capabilities. For teleconferencing, where the number of users of a given video feed is relatively small, e.g. tens or hundreds, cost and accordingly bandwidth usage must be relatively small.
It is known to use a single fixed camera in a video teleconference, which provides little flexibility. An improvement is to have a human cameraman walk around and manipulate the camera lens to provide a view of interest, for example a wide view of an audience or a close-up of a speaker. Multiple views can be provided by having multiple cameramen, cameras, and special processing equipment and a director to select between the views. However, this can be expensive.
Similarly, it is known to have a user camera that can be remotely controlled, (e.g. pan, tilt, zoom), by a viewer. However such methods are costly and cumbersome, and the physical movement of the camera relatively slow. In addition, a single viewing image is provided at a given time.
It is also known to use an electronic whiteboard, where an image, such as marks on a whiteboard or digitally stored slides, are sensed electronically and transmitted to a remote location. However, this requires having an electronic whiteboard at the live site, which may not always be possible, due to, for example, problems related to mobility and connections. In addition, the user still is afforded little choice of views.
A problem with known methods is that they do not economically provide a way for multiple individuals to obtain details of a sub-image while also providing an overview of the image. Such as view would mimic human habits of focusing on various areas of interest (xe2x80x9cattention pointsxe2x80x9d or xe2x80x9cattention windowsxe2x80x9d) from time to time while retaining peripheral vision of a broader field (xe2x80x9cwhole-eye-viewxe2x80x9d or xe2x80x9cwide angle viewxe2x80x9d). For example, the viewer may focus on a speaker""s face, then on a slide that is being projected, while all along noticing movements occurring throughout the room.
A way to provide flexibility to the user would be to allow him to designate an attention window on a normal video window, and to display this area at an enlarged size. A major problem with such an approach is that because current videoconference data is provided at relatively low resolution due to bandwidth limitations, an enlarged image would provide a low quality or blurry image, which would be of limited use.
Another way to provide a system that more closely mimics human vision would be to send a high resolution image of the whole-eye-view to each member of the electronic audience (xe2x80x9cuserxe2x80x9d or xe2x80x9cclientxe2x80x9d). The entire view could be displayed either at high resolution or at some reduced resolution, assuming the client has sufficient processing power. Each client can be configured so that attention windows can be expanded to achieve detail; because of the high resolution of the data, the expanded image would still provide a relatively sharp image. However, due to present day limitations in bandwidth (as well as processing speed at clients), sending so much data is expensive, impractical and in some cases impossible. (Using technology commonly in use today, it is generally desirable that a videoconference operate over as little as about 128 kilobits per second (assuming dual channel ISDN), although that will change as DSL, Cable and other improved connections become more common. A typical web or video conference may have about VGA resolution (640xc3x97480 pixels) or less.)
Digital video teleconferencing is becoming increasingly popular and is being used in increasingly diverse applications. Accordingly, it would be advantageous to provide an economical way to provide video teleconferencing that would allow a user to experience an event in a manner more closely approximating being present at the event, while not requiring prohibitive amounts of bandwidth.
Systems and methods for providing digital video teleconferencing over a network that allows a user to view the event in a manner more closely approximating live viewing are provided, while not requiring excessive use of bandwidth. Low resolution and high resolution views of a videoconference event are obtained, preferably by using two cameras at the event. A whole eye view is sent to clients at low resolution. A user at the client can select one or more areas of interest to him (xe2x80x9cattention windowsxe2x80x9d). High resolution data from the attention window(s) selected by each user is sent to the respective client. The client displays the whole eye view and the attention window data.
In one embodiment of the invention, a method for providing video teleconferencing is provided. A low resolution data stream comprising an image of a first field of view from an event and a high resolution data stream comprising a second image of a second field of view are received at a server. The first field of view and the second field of view have areas of overlap. The server sends the low resolution data stream to a plurality of clients. The client also sends a subset of the high resolution data stream to each of the plurality of clients.
In another embodiment, a system for providing teleconferencing is provided. The system includes two cameras. The cameras are disposed so that their fields of view overlap. One of the cameras sends a low resolution data stream to a first computer, which sends the low resolution data stream to one or more clients. Similarly, the other camera sends a high resolution to a computer, which can be the same computer or a different computer as the first computer. For each of the clients, the computer sends a portion of the high resolution data stream to the client. The portion of the data sent can be different for each client.
In another embodiment, a method for providing video conferencing at a client is provided. Incoming high resolution data is displayed. Incoming low resolution data is displayed, resulting in a low resolution display. When a user request to select an attention point is received, the attention point information associated with the user request is sent to a source of the high resolution data.